count occurrences of word in string java code example

Example 1: how to find occurrence of words in string

HOW TO COUNT OCCURRENCE OF THE WORDS IN STRING 
(It can also be solved by using nested for loops...)

String str = "I am happy and why not and why are you not happy you should be";
   String [] arr = str.split(" ");
   Map<String, Integer> map = new HashMap<>();

   for (int i=0 ; i < arr.length ; i++){
       if (!map.containsKey(arr[i])){
            map.put(arr[i],1);
           } else{
         map.put(arr[i],map.get(arr[i])+1);
        }
        }
     for(Map.Entry<String, Integer> each : map.entrySet()){

    System.out.println(each.getKey()+" occures " + each.getValue() + " times");
    }

Example 2: count occurrences of character in string java 8

String someString = "elephant";
long count = someString.chars().filter(ch -> ch == 'e').count();
assertEquals(2, count);
 
long count2 = someString.codePoints().filter(ch -> ch == 'e').count();
assertEquals(2, count2);

Example 3: check how many of a word is in a string

function countOccurences(str,word)  
{ 
    // split the string by spaces in a 
    String a[] = str.split(","); 
  
    // search for pattern in a 
    int count = 0; 
    for (int i = 0; i < a.length; i++)  
    { 
    // if match found increase count 
    if (word.equals(a[i])) 
        count++; 
    } 
  
    return count; 
}

Example 4: find number of occurrences of a substring in a string java

public static int count(String str, String target) {
    return (str.length() - str.replace(target, "").length()) / target.length();
}

Example 5: how to count words in string in java

String str = "I am happy and why not
  and why are you not happy and you should be";
        String [] arr = str.split(" ");
        Map<String, Integer> map = new HashMap<>();

        for (int i=0 ; i < arr.length ; i++){
                if (!map.containsKey(arr[i])){
                    map.put(arr[i],1);
                } else{
                    map.put(arr[i],map.get(arr[i])+1);
                }
        }
        for(Map.Entry<String, Integer> each : map.entrySet()){

  System.out.println(each.getKey()+" occures " + each.getValue() + " times");
        }